Conventionally, in the manufacturing process of the industrial product, a power assist apparatus is used as an apparatus assisting an operator in conveying and assembling a work (a heavy work). For example, the workflow of assembling the work includes the following workflows; conveying the work; and setting the work. Conveying the work cooperated with the apparatus, the operator can give the burden conveying the work to the apparatus, and can set the work efficiently after teaching the information involving the conveying route and the assembling position to the apparatus. Thus, the purposes of using the apparatus are reducing the operator's working burden and improving the workability.
For example, as the power assist apparatus, JP-H11-245124-A discloses the work lifting apparatus detecting the inclination of a holder holding the work and lifting the holder to set the inclination to the reference inclination set in advance.
According to these conventional apparatuses, the operator's working burden can rightly be reduced with respect to the conveying the work. However, depending on only the apparatus when setting the work, the variable position of assembling object causes the setting failure of the work.
The objective of the present invention is to provide an unexpected power assist apparatus and its control method, enabled to reduce the operator's working burden and to improve the setting precision and the workability, when the operator sets the work by using the apparatus, giving a part of the operator's working burden of setting the work to the apparatus, making good use of the operator's decision or experience.